Update Import-Certificate.md --FilePath option

This commit adds important information on the usage and behavior of the
`Import-Certificate` Powershell cmdlet, specifically around the importing
of multiple certificates at once.

Author: saifshaikh48

docset/winserver2012-ps/pki/Import-Certificate.md

@@ -80,6 +80,8 @@ Accept wildcard characters: False
 Specifies the path to a certificate file to be imported.
 Acceptable formats include .sst, .p7b, and .cert files.
 If the file contains multiple certificates, then each certificate will be imported to the destination store.
+The file must be in .sst format to import multiple certificates;
+otherwise, only the first certificate in the file will be imported.
 
 ```yaml
 Type: String

docset/winserver2012r2-ps/pki/Import-Certificate.md

@@ -82,6 +82,8 @@ Accept wildcard characters: False
 Specifies the path to a certificate file to be imported.
 Acceptable formats include .sst, .p7b, and .cert files.
 If the file contains multiple certificates, then each certificate will be imported to the destination store.
+The file must be in .sst format to import multiple certificates;
+otherwise, only the first certificate in the file will be imported.
 
 ```yaml
 Type: String

docset/winserver2016-ps/pki/Import-Certificate.md

@@ -85,6 +85,8 @@ Accept wildcard characters: False
 Specifies the path to a certificate file to be imported.
 Acceptable formats include .sst, .p7b, and .cert files.
 If the file contains multiple certificates, then each certificate will be imported to the destination store.
+The file must be in .sst format to import multiple certificates;
+otherwise, only the first certificate in the file will be imported.
 
 ```yaml
 Type: String

docset/winserver2019-ps/pki/Import-Certificate.md

@@ -85,6 +85,8 @@ Accept wildcard characters: False
 Specifies the path to a certificate file to be imported.
 Acceptable formats include .sst, .p7b, and .cert files.
 If the file contains multiple certificates, then each certificate will be imported to the destination store.
+The file must be in .sst format to import multiple certificates;
+otherwise, only the first certificate in the file will be imported.
 
 ```yaml
 Type: String

docset/winserver2022-ps/pki/Import-Certificate.md

@@ -100,7 +100,8 @@ Accept wildcard characters: False
 
 Specifies the path to a certificate file to be imported. Acceptable formats include `.sst`, `.p7b`,
 and `.cert` files. If the file contains multiple certificates, then each certificate will be
-imported to the destination store.
+imported to the destination store. The file must be in `.sst` format to import multiple
+certificates; otherwise, only the first certificate in the file will be imported.
 
 ```yaml
 Type: System.String